Pretensioned concrete members are designed and manufactured by using at least two materials: concrete and prestressing reinforcement. Also, two main stages must be considered: prestress transfer and member loading. Hence, ...[+]

Pretensioned concrete members are designed and manufactured by using at least two materials: concrete and prestressing reinforcement. Also, two main stages must be considered: prestress transfer and member loading. Hence, the behavior of these members depends strongly on the reinforcement-to-concrete bond performance and prestress losses. In this paper, a testing technique to measure the specific parameters related with the involved phenomena is presented. The testing technique is based on the analysis of series of specimens varying in embedment length to simulate several cross sections at only one end of a pretensioned concrete member. Each specimen is characterized by means of the sequential release of the prestress transfer (detensioning) and the pull-out (loading) operation. The test provides data on prestressing force, transmission length (initial and long-term), anchorage length (without and with slip), reinforcement slips, bond stresses, longitudinal concrete strains, concrete modulus of elasticity, and prestress losses (instantaneous and time-dependent).[-]

The content of this paper is part of the research that the Institute of Concrete Science and Technology (ICITECH) at Universitat Politecnica de Valencia is currently conducting in conjunction with PREVALESA and ISOCRON. ...[+]

The content of this paper is part of the research that the Institute of Concrete Science and Technology (ICITECH) at Universitat Politecnica de Valencia is currently conducting in conjunction with PREVALESA and ISOCRON. This study has been funded by the Ministry of Education and Science/ Science and Innovation and ERDF (Projects BIA2006-05521 and BIA2009-12722). The authors wish to thank the aforementioned companies as well as the technicians at the concrete structures laboratory of the Universitat Politecnica de Valencia for their cooperation. Finally, the authors wish to pay their respects to C.A. Arbelaez.[-]